1. Field of the Invention
The present invention relates to a modular control system having a housing and inner modules, for use with subsea installations or for use in harsh weather conditions such as on oil and gas rigs wherein one or more of the inner modules may be removed and replaced without having to shut down the entire control system.
The invention relates to a subsea Christmas tree using the unique modular control system. The invention further relates to a manifold which is operated using the inventive modular control system. The invention also relates to a distribution unit having a modular control system.
2. Background of the Invention
Various control systems usable for harsh environments have existed for some time, see for example U.S. Pat. No. 4,899,822 which is incorporated herein by reference. Most references simply teach mounting entire, watertight control systems on a subsea installation, such as a Christmas tree, or on an oil rig without being able to remove separate components.
The present invention is directed to a modular control system having a main outer housing, a plurality of removable modules, wherein each inner module comprises a rear side, a front side, two sidewalls and a top and a bottom. The rear side is constructed to support a hydraulic connector or an electrical connector or both which can engage control valves. The connectors can be attached with pressure-balanced couplings and a retaining device or latching assembly can be used to hold the inner modules into the outer housing. Handles or similar devices can be installed on the inner module so an ROV (Remotely Operated Vehicle) can be used to engage or detach the inner modules separately, without the need to remove all modules from the outer housing.
The elements of the modular control system can include solenoid control valves, many other valves, various sensors and filter elements for use in operation of the subsea well head.
It is an object of the invention to provide detachable modular control units which are capable of multiple functions such as valve control, pressure monitoring, fluid filtration, flow measurement, chemical injection dosage rate control, pressure monitoring, signal dampening, signal amplification, and various other subsea or drilling related functions.
It is an object of the present invention to provide a subsea installation having separate individual detachable electronic control modules which can be installed by an ROV on a subsea installation with each module capable of controlling a plurality of operating functions and a plurality of control valves.
A further object of the present invention is to provide mountable electronic modules which are detachably mounted on the subsea installation and capable of receiving signals from a host or a subsea master control stations for the control and command of adjacent or remote control valves or other electronic components which are incorporated into the detachable subsea modules.
An object of the invention is to have easily replaceable components, which are watertight and capable of being pulled and re-engaged by a remotely operated vehicle, or a diver.
Other objects and advantages of the invention will become apparent from the attached description, figures and appended claims.